在后台根据单据标识构建单据的DynamicObject，然后调用BOS的保存服务保存单据。

var bussnessInfo = Kingdee.BOS.ServiceHelper.MetaDataServiceHelper.GetFormMetaData(this.Context, "FormId").BusinessInfo;
var billDynamicObjectType = bussnessInfo.GetDynamicObjectType();
DynamicObject billobj = new DynamicObject(billDynamicObjectType);
Kingdee.BOS.ServiceHelper.BusinessDataServiceHelper.Save(this.Context, bussnessInfo, new DynamicObject[]{billobj});